In recent years, imaging apparatuses which perform image capturing using an image sensor such as a CCD image sensor (Charge Coupled Device Image Sensor) or a CMOS image sensor (Complementary Metal Oxide Semiconductor Image Sensor) are in widespread use.
In an image sensor, a large number, several hundred or more for example, of image capturing elements (pixels) are used, and these image capturing elements (pixels) each have fixed pattern noise. As an example of the fixed pattern noise, there is dark current shading or the like for example.
It is possible that data related to the fixed pattern noise are measured in advance and stored in a camera head or the like, and when the imaging apparatus is activated, for example, they are read and sent to a CCU (Camera Control Unit) or the like to be used for video processing of a captured video signal or the like.
However, as described above, the image sensor has a large number of image capturing elements (pixels) which each have fixed pattern noise, and thus it has been time consuming to transmit the fixed pattern noise to the CCU or the like. That is, in an imaging apparatus such as an endoscope, the amount of data related to noise data or the like of image capturing elements stored in a head unit has become large. Accordingly, a transmitting time for sending these data to a control unit such as the CCU becomes long, and it will take much time to output video on which the noise data of the image capturing elements are reflected.
Thus, it is possible that, for example, a time of about ten seconds is taken from turning on the power of the imaging apparatus until outputting video on which data related to the fixed pattern noise of the above-described image sensor are reflected.